JPH082397Y2 - Side rail mounting structure - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to, for example, a structure for mounting a horizontal crosspiece that is horizontally mounted on a column of a stepladder.

[Conventional technology]

The stepladder is a combination of a pair of left and right columns arranged in front and rear, and a horizontal rail or a tread plate is attached between the columns. Each strut is made of extruded material such as aluminum, and when attaching a horizontal crosspiece to this, the horizontal crosspiece is inserted into a hole having substantially the same cross-sectional shape as the horizontal crosspiece formed on the inner surface of the left and right strut facing each other. The screw was screwed in while tapping from the outer surface on the opposite side of the column into a single screw hole formed in the middle of the end surface of the cross rail.

[Problems to be solved by the device]

However, if the horizontal rail attached to the support column is a round bar having a substantially circular cross-sectional shape, the round bar will also rotate when screwing the screw toward the screw hole. However, there is a problem that it is difficult to screw the screw efficiently and smoothly, because the screw must be screwed by tapping while preventing the rotation of the round bar. In addition, there is a problem in that the horizontal rail, which is fastened to the support post with a screw, may be loosened at the screw fastening point due to vibration or impact after fastening, which adversely affects the quality of the product.

Therefore, the present invention has been made based on the above circumstances, and provides a cross rail mounting structure capable of smoothly and efficiently fastening the support leg by screwing and preventing loosening of the screw after fastening. The purpose is to

[Means for solving the problem]

The present invention for achieving the above-mentioned object is to form a circular hole in the inner surface of each extruded strut facing each other, and insert a horizontal bar of a round bar having a substantially same cross-sectional shape into the circular hole. It is configured by forming a screw hole on the horizontal rail into which one tapping is screwed from the outer surface side of the support column toward the end surface of the horizontal rail, at an eccentric position deviated from the center of the shaft center.

[Action]

According to the present invention configured as described above, the position of the single screw hole is displaced from the center of the circular end face of the horizontal rail when the screw is tapped into the screw hole of the horizontal rail from the outer surface side of each column and screwed. The rotation of the cross rail around the screw hole in the circumferential direction is blocked by the peripheral edge of the circular hole of the support column, and the cross rail does not rotate together with the screwing of the screw.

〔Example〕

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

FIG. 2 shows an example of a stepladder to which the cross rail mounting structure of the present invention is applied. That is, the pair of left and right front struts 1,1 and rear struts 2,2 arranged in front and back are both made by extrusion molding using aluminum etc., and front hinge 3A and rear The upper end tool 3 to which the hinge 3B is coupled is connected, and the front and rear struts 1 and 2 are swingably openable and closable about the stop shaft 4 as a fulcrum. Front support 1,1
Upper and lower round bar-shaped horizontal rails 5 and 6 which are laid horizontally with a space between them.
Each of the upper and lower treads 7 and 8 is rotatably supported at one end thereof, and the upper step is located between the rear columns 2 and 2 at a height position corresponding to the upper horizontal rail 5. A round bar-shaped horizontal rail 9 for locking and supporting the tread 7 is provided, and a reinforcing rail 10 is provided below the horizontal rail 9.

As shown in Fig. 1 (a) and (b), each round bar-shaped horizontal rail 5,
6,9 both end portions of which are fitted with circular holes 11 having substantially the same cross-sectional shape as the horizontal rails formed on the inner surfaces of the left and right columns 1, 1 and 2, 2 facing each other. The end surface of 9 is in contact with the bottom lower surface of a groove 12 formed along the longitudinal direction on the outer surface side of each of the columns 1, 1 and 2, 2. As shown in FIG. 1 (C), only one screw hole 13 is formed in the axial direction from the end face of each horizontal rail 5,6,9.
An eccentric portion D deviated from the center C of the shaft center is provided as a center, and one tapping screw 14 is screwed into the groove 12 toward the screw hole 13. Further, the reinforcing bar 10 has an elliptical cross-sectional shape, and although not shown, each of the columns 1,
The reinforcing bars are fitted into the elliptical holes formed on the inner surfaces facing each other of 1 and 2, and the end surface of the reinforcing bar 10 is brought into contact with the bottom surface of the bottom of the groove 12.
A tapping screw is screwed into the groove 12 from the groove 12 toward the screw hole 10. A decorative bar 15 for concealing the screw head 14A exposed in the groove 12 is fitted in the groove 12 of each of the columns 1 and 2.

Both side edges of the upper tread plate 7 and both side edges of the lower tread plate 8 are connected by hanger links 16,16, and the upper and lower tread plates 7,8 are interlocked via the hanger links 16,16. The lower tread 8 is held. The pair of guide rods 17, 17 provided so as to face each other along the inner side of the upper part of the rear support columns 2, 2 are held at both ends by upper and lower receiving members 18, 19 attached to the upper end tool 3 and the cross rail 9, respectively. An elliptical connecting ring 20 that is inserted into the guide rods 17 and 17 is swingably attached to both side edges of the upper step plate 7 (see FIG. 1 (a)), and the horizontal rail 5 is used as a fulcrum. As a result, the rear columns 2, 2 are interlocked with the upper step plate 7 that pivotally moves to open and close in the front-rear direction.

[Effect of device]

As described above, according to the present invention, the eccentricity is offset from the center of the axial center in the axial direction from the end surface of the round bar-shaped horizontal rail in which a circular hole is formed in the inner side of each strut and the tapping screw is screwed in from the outer side. Since a single screw hole is provided at the location, even when the tapping screw is screwed into this screw hole, the horizontal rail does not rotate together with the screw, so that the horizontal rail can be attached to the pillar smoothly and efficiently. You can Further, even after the horizontal rail is attached, the fastened screw does not loosen even if it receives an impact, and a strong product can be provided.

[Brief description of drawings]

FIGS. 1 (a), (b) and (c) show an embodiment of the present invention. FIG. 1 (a) is a perspective view of the main part, and FIG. 1 (b) is FIG. 1 (a). 1 is a sectional view taken along the line AA of FIG. 1, FIG. 1 (c) is an enlarged sectional view of a cross rail, and FIG. 2 is a perspective view showing an example of a stepladder to which the present invention is applied. 1,2 …… Posts, 5,6,9 …… Horizontal crosspieces, 11 …… Circular holes, 13 …… Screw holes, 14 …… Tapping screws, C …… Shaft center, D
…… Eccentric place.

Claims (1)

[Scope of utility model registration request] 1. A cross rail having a circular cross-sectional shape that is substantially the same as the circular hole (11) in a circular hole (11) formed in the facing inner surfaces of the extruded columns (1, 2). Insert (5,6,9),
A horizontal rail (5,6,9) in which one tapping screw (14) is screwed from the outer surface side of each strut (1,2) toward the end surface of the horizontal rail (5,6,9).
Screw bar (13) is provided at an eccentric portion (D) deviated from the center (C) of the shaft center, and a horizontal crossbar mounting structure is provided.